Careful if you lubricate your reels because too much lube can cause problems. If you are not sure where to apply the lube and how much to apply take it to a professional.
Check your guides regularly. If there is a crack, take it to your nearby tackle shop to get it replaced. Your line can rub on this crack and break if you don't replaced it, especially when you catch a big fish.
If you keep your fishing rods and reels in the garage for storage, Wrap a plastic grocery sack around the reels and get a twisty tie to tie it off. This will keep dust and dirt out of them.